OBJECTIVE:. The objective of this project is to develop successful clinical strategies for the early detection and treatment of esophageal cancer. BACKGROUND: Esophageal cancer has a very poor prognosis, primarily because most tumors produce symptoms only after they have spread beyond the esophageal wall and are unresectable. Significant improvement in survival will require successful strategies to diagnose and treat more cases at earlier, more curable stages of the disease. METHODS: The project includes five studies: the Cytology Sampling Study (CSS), the Mucosal Staining Study (MSS), the Endoscopic Staging Study (ESS), the Endoscopic Therapy Pilot Study (ETPS), and the Chemoregression Study (CRS), each designed to evaluate a technique that may be useful in a practical early detection and treatment program. The project is being carried out in Linxian, China, a county with very high rates of esophageal cancer. PROGRESS: In the past year, field work has been performed in three of the studies. In the ESS Study, 50 endoscopically evident esophageal lesions were scanned by optical coherence tomography (OCT), a new optical imaging technique which we hope can identify the depth of invasion or early invasive cancers. The OCT scans were performed before and after endoscopic mucosal resection of the lesions, and the scan tracings are now being compared with the histology of the resected specimens. In the ETPS Study, we performed endoscopic mucosal resection (EMR) on 57 lesions in 52 patients, and performed argon plasma coagulation (APC) on 53 additional lesions in 31 patients. Follow-up of these patients, to evaluate the effect of these treatments, is currently being done. In the CRS, we randomized 360 patients with biopsy-proven mild or moderate squamous dysplasia (a precursor lesion for squamous esophageal cancer) to one of four treatment groups, taking oral doses of selenomethionine 200 ug once a day, celecoxib 200 mg twice a day, both medications, or neither. Pill delivery and patient monitoring is ongoing. After 10 months of medication, the patients will be endoscoped and biopsied again, to evaluate the effect of each treatment regimen on the progression or regression of the patients' esophageal disease.